Conventionally, an energization test is performed on test objects, such as semiconductor integrated circuits, to determine whether or not the test objects are produced to the exact specification. An inspection device, to which an inspection unit provided with a probe card having probes which are pressed against respective electrodes of the test object is attached, is used in such an energization test. An inspection unit of this type is used to connect the electrodes of a test object to a tester electrically for inspection.
An inspection unit for use in such an energization test includes, a probe card having a plurality of probes to be brought into contact with a test object on a first surface, a pogo pin block located on the side of a second surface of the probe card, a wiring board located on the opposite side of the probe card with respect to the pogo pin block and electrically connected to the probes of the probe card via pogo pins extending through the pogo pin block, and a reference body located on the opposite side of the pogo pin block as a connection body with respect to the wiring board to prevent the probe card from being bent or distorted. The inspection unit is assembled by uniting the probe card, the pogo pin block, the wiring board, and the reference body, with fastening means.
The number of probes mounted on the probe card is at least several hundreds, and sometimes as many as several tens of thousands.
In the conventional probe described above, when inspection of a test object is repeated, an amount of protrusion from the probe card, i.e., height, is reduced due to wear or some other reason. Then, the worn probes cannot contact the corresponding electrodes of the test object.
The inspection unit cannot fulfill its full function as an inspection unit even when one probe does not contact the corresponding electrode of the test object due to wear or some other reason. In this case, the inspection unit must be replaced with a new one. However, the replacement of the entire inspection unit, including the pogo pin block, the wiring board, and the reference body, for wear of only one probe is such a waste considering efficient use of the component parts, and it places a significant economic burden on the user.
As a remedy, there is a test object inspection device in which the probe card is detachable from other constituent members of the inspection unit so that only the probe card, not the entire inspection unit, can be replaced (refer to Patent JP 2012-163410 A).
FIG. 1 of JP 2012-163410 A illustrates an inspection unit including the probe card supported by a card table at its periphery, the pogo pin block, the wiring board, and a performance board as the “reference body.” In this inspection unit, the probe card is separable from the pogo pin block, the wiring board, and the performance board (reference body). The separable structure is as follows.
The probe card and the performance board (reference body) are united together by a suction force based on the negative pressure in a vacuum chamber formed therebetween. The probe card and the performance board (reference body) are united together when a negative pressure is created in the vacuum chamber, and the probe card and the performance board (reference body) become separable when the pressure in the vacuum chamber is returned to an atmospheric level.
The vacuum chamber is defined by a ring-shaped seal member provided between the probe card and the performance board (reference body). The seal member functions as a seal member when the probe card and the performance board (reference body) are brought into contact from a separated state. Then, when the space defined by the seal member, the probe card, and the performance board (reference body) is decompressed into a desired vacuum state (decompressed state) with a vacuum pump or the like, a vacuum chamber with a negative pressure is formed.
When the probe card and the performance board (reference body) is united together by the negative pressure, the relative position between the probe card and the performance board (reference body) is determined by an anchor (intermediate body) located between the probe card and the performance board.
When the probe card is replaced, the vacuum chamber is returned from the vacuum state to the atmospheric pressure, and the suction force created by the negative pressure disappears, making it possible to separate the probe card from the performance board (reference body). Therefore, the probe card can be replaced easily in the inspection unit.